Ask-A-Linguist Message Details

Subject:

Lateral Lisp sound in African languages?

Question:

I've listened to a good amount of African (largely South African)
music in the last few years, and it sounds to me that in one or
more languages (perhaps Zulu, for one) there is actually a sound
that sounds like a lateral lisp. I've noticed this with several
different artists (e.g. both Zola and Ladysmith Black Mambazo), and
they all are able to pronounce ''s'' sounds properly, which suggests
to me that it's not a speech impediment but an actual part of the
language's phonology.
I've searched around online, but I haven't been able to find any
reference to this! Am I imagining things? What is this sound that
I'm hearing?
Thanks!